feat: Implement Chainlink-Based Oracle/Validator System for Bridge

[JamesVictor-O]

Objective

Design and implement a validator system using Chainlink's CCIP (Cross-Chain Interoperability Protocol) or Oracles to secure the token bridge by verifying cross-chain transfers between Base and the secondary network.

Requirements

1. Integrate Chainlink CCIP or custom Chainlink Oracles to validate cross-chain transfers
2. Implement signature verification mechanism for bridge messages
3. Create a reliable validation system that ensures transfer authenticity
4. Design stake-based security model for validators (if using custom oracle setup)
5. Establish slashing conditions and mechanisms for misbehaving validators

Technical Specifications

• Use Chainlink CCIP for direct cross-chain messaging (preferred approach)
• OR implement custom Chainlink Oracle network with multiple validators
• Create validation logic for verifying transaction proof from source chain
• Implement multi-signature requirement for high-value transfers
• Design robust verification process that checks:
• Transaction inclusion proofs
• Message authenticity and integrity
• Proper sequence/nonce progression
• Establish configurable thresholds for validation requirements based on amount

Security Considerations

• Implement minimum validator threshold for consensus
• Create time-locks for large transfers
• Design fraud-proof system to challenge suspicious validations
• Implement circuit breaker for unusual activity
• Include validator rotation mechanism to prevent centralization

Stake and Slashing (if using custom oracle network)

• Design staking contract for validators to deposit security bonds
• Implement slashing conditions for:
• Double validation
• Validating invalid transfers
• Downtime/non-participation
• Collusion
• Create incentive structure for honest validation
• Implement claim period for disputing incorrect validations

Chainlink Integration

• Specify required Chainlink node operators and job specifications
• Define oracle data format and validation parameters
• Implement proper use of Chainlink's security features
• Configure appropriate gas parameters for cross-chain operations
• Ensure compatibility with Chainlink's fee model

Testing Requirements

• Comprehensive testing of oracle validation logic
• Simulation of various attack vectors
• Test validator slashing conditions
• Verify correct handling of network disruptions
• Test extreme market conditions (high gas, network congestion)

Deliverables

• Smart contracts for validator/oracle system
• Integration with both bridge core contracts
• Chainlink job specifications and node requirements
• Comprehensive test suite
• Technical documentation explaining the validation mechanism
• Operational documentation for maintaining the oracle network

Suggested Approach

1. Begin with Chainlink CCIP integration (if suitable for requirements)
2. If custom solution needed, implement base validator contracts
3. Develop staking and security mechanisms
4. Create validation logic and signature verification
5. Integrate with both bridge contracts
6. Comprehensive testing and security review

Definition of Done

• Oracle system successfully validates legitimate cross-chain transfers
• Invalid or malicious transfers are rejected
• Stake/slash mechanism correctly incentivizes honest validation
• System handles network disruptions gracefully
• All tests pass with >95% coverage
• Security review completed with no critical issues